There has been a conventional pressure sensor of the type having such a structure that a housing is hermetically sealed to a glass support which is fixed to a semiconductor strain gauge by means of anodic bonding.
For instance, such a pressure sensor is disclosed in U.S. Pat. No. 3,697,919 issued on Oct. 10, 1972 and titled "Semiconductor Pressure Transducer Structure".
In this prior art, the glass support is hermetically sealed to the housing by a wedge-shaped seal in the manner that the glass support is fastened by tapered walls of a wedge-shaped seal which faces to inside tapered walls of the housing. The tapered walls of the wedge-shaped seal must be long along the axial direction thereof. Because, if the tapered walls of the wedge-shaped seal are short, stresses caused by measuring pressure are applied concentrically to the inside walls of the housing with small areas. The semiconductor strain gauge has to be disposed apart from the tapered walls of the wedge-shaped seal for avoiding the fastening stress of the walls. Then, the prior art is provided with a long structure of the glass support along the axial direction thereof.